An incorrect claim usually leads to a loss for the claimer. But not always: in 'I told you so!' part 1 (here) the claimer profited from his wrong claim.
In his classic The Expert Game Terence Reese describes how an incorrect claim unexpectedly turned out well. Although he was the victim, he saw the funny side of it. (The story below is the last deal of the last chapter —The Vice, The Winkle and the Stepping-Stone — handling about entry-squeezes).

		♠	K 9
		♥	A 10 6 4 2
		♦	Q J 10
		♣	A Q 8
♠	8 5 2			♠	A Q J 10 3
♥	J 8 7 3			♥	K Q 9
♦	9 6 4 3			♦	A 5
♣	10 5			♣	7 4 2
		♠	7 6 4
		♥	5
		♦	K 8 7 2
		♣	K J 9 6 3

To me humour is an essential part of bridge. If there is not an occasional burst of laughter something is missing, I think.
The grand slam below is such a side-splitter. It originates from the English Mixed Teams Championship 1956. South blundered and as a result she made a grand slam in an unbelievable way. Without the blunder she almost certainly wouldn't have made it.

To read two earlier columns on this subject click here (part one) and here (part two).
The 'Mother of all "double-or-pass" problems', below, is not named as such because it is a difficult problem (it isn't) but because the consequences of the wrong decision were so spectacular.
The deal is from the Germany − Sweden match during the 1997 European Teams Championships in Montecatini (Italy). Swedish crack Peter Fredin was faced with the following problem (?) — by the way: according to the championship's Daily Bulletin the player in question was Fredin's partner Eriksson but all later publications make it clear Fredin was the culprit:

N/—
♠	A K 10 6 3 2
♥	6 2
♦	Q J 6 4 3
♣	—

Should West double or pass?

West's 2♠ bid is one of the very few bids in an opponent's suit that is natural. It says: 'So what if South has a weakish four-card spade suit? That doesn't bother me since I have at least a good six-card spade suit and a very good hand.'

In the first article (here) two questions turned out to be important when considering 'penalty double or pass': can the opponents escape to a better contract and, if yes, will they?
Sometimes another issue influences our decision to double or not: often contracts are only beaten on a special opening lead. If the player contemplating the double is not to lead himself he must ask himself what influence his double may have on partner's choice of opening lead.
If he fails to do so, he can regret that very much, as is shown in the following comical (to NS, that is) catastrophe. The year is 1964, the place is Toronto, the tournament the Men's Pairs (MP-scoring) during the ACBL Summer Nationals.

Let's take a look at a traditionally difficult (for the most psychologically) bidding decision: should one, playing with IMP-scoring, double a contract that will certainly go down a lot (or can go down a lot, provided that partner finds the right lead) if there is a risk that the opponents escape to a makable contract? (Playing with MP-scoring, the question applies too, if the contract is expected to go only one or two down; in that case there is a second risk: the double warns declarer who may subsequently even make the contract).
The argument in favour of the double: why scorn a juicy +500 or +800 and be satisfied with a mere +150 or +200? Often the opponents do not have an escape available. And even if they have, they will often stay put, afraid of going out of the frying pan into the fire. (Playing with MP-scoring a double can even be necessary if +200 scores a top and +100 a bottom; not doubling can be very costly then, if it turns out declarer cannot avoid going down one).
The argument against doubling is the 'bird in the hand'-principle: just take the plus score instead of doubling greedily and noting something like −1190 a little later (of course real men double them in their escape as well...).

As in my earlier 'Unbelievable Contracts' the deal described below is not fiction, but comes from real play. And as I wrote in those earlier articles: every bridge player can fill a book with his own funny, beautiful or ridiculous deals... if only he makes a note of them directly after play. But since few players actually do so, many potentially good stories are being lost.

Once again I wasn't playing with my regular partner (obviously playing with non-regular partners creates the most exciting deals...), when I was dealt the following hand as South: